Local brightness mechanisms sketch out surfaces but do not fill them in: Psychophysical evidence in the Kanizsa square

In two experiments, brightness enhancement of the illusory surface in the Kanizsa square was investigated by means of a brightness matching procedure. The results show that specific properties of the inducing elements such as size, spacing, and luminance have effects on the matching threshold that are similar to those previously obtained in experiments on simultaneous con trast. The data from a third experiment demonstrate that increment thresholds measured within the Kanizsa square are elevated when the target is flashed on a position close to the inducing elements. The thresholds decrease considerably in the center of both test and control figures (representing or not representing an illusory square). These observations suggest that low-level mechanisms are likely to explain local brightness differences within the configurations but not global figure brightness. In other words, local contrast seems to generate brightness information that “sketches out” surfaces at their surrounds but does not “fill” them “in.”     

Quality of life: Criteria for behavioral adjustment(1)

New insights into potentially harmful consequences of modern technology have increased efforts to use the methods of the social, behavioral, and biological sciences in searching the psychosocial environment for aversive factors and in identifying high-risk individuals and groups. Examples are given from an ongoing project concerned with the impact of technology on workers, health and satisfaction, in particular problems concerned with adjustment to underload and overload associated with automation and mechanization in industry. Furthermore, the stress involved in urban commuting is illustrated with psychophysiological data. On the basis of results obtained in these and related studies it is argued that a moderately varied flow of stimuli and events, opportunities to engage in psychologically meaningful activities and to exercise personal control over external conditions, may be considered key components in the quality-of-life concept. Health risks associated with adjusting to demands characteristic of life in technologically advanced countries are discussed in this context.     

Quantitative approaches in environmental studies

Psychological scaling methods can be applied and can bring substantial knowledge to bear upon problems within the realm of environmental hygiene. Methodological issues related to the possibility of obtaining calibrated scales of perceptual variables such as discomfort, annoyance, and unpleasant odors are critical when the scale values are to be entered into a physical pollution index or a perceived environmental quality index, both being applied in the form of norms or recommendations. The level of measurement (ordinal, interval, or ratio scale) is related to the question of calibration of scales. From a practical point of view, the effects of observer-environment dependence are important to disguise in the scale values. Problems having to do with calibration of scales and with application of knowledge about perceptual processes to the scales are being explored in ongoing research projects. These include the measurement of temperature discomfort in different climates and the measurement of annoyance in areas with different noise exposures. Attempts have been made to solve an odorous air pollution problem with psychological measurements.     

Anticipation of electric shock: A psychophysical study

Successive measures of emotional intensity were obtained by a two-step scaling procedure from 23 subjects anticipating an electric shock to be given at the end of a 45-min period. Half of Ss had a clock available, while the other half had to estimate apparent time. The emotional reaction was shown to increase exponentially as time before shock decreased. Heart rate also increased as time for shock was approaching, but the trend was not regular.     

SUBJECTIVE INTOXICATION INDUCED BY NITROUS OXIDE IN VARIOUS CONCENTRATIONS

F rankenhaeuser , M. & J arpe , G. Subjective intoxication induced by nitrous oxide in various concentrations. Scand. J. Psychol ., 1962, 3 , 171–176.—Subjective intoxication at various dose-levels of nitrous oxide was investigated by the method of magnitude estimation. Estimates of intoxication were obtained from the intoxicated subjects themselves and from a group of observers. Both these sets of subjective scale values showed a pronounced and regular increase with increasing dose-levels of the drug. Objective performance changes followed the same general pattern, but were much less pronounced. It was concluded that subjective scaling methods are well suited for measurements of drug-induced changes in subjective variables.     

CATECHOLAMINE EXCRETION, PERFORMANCE, AND SUBJECTIVE STRESS

Psycho-endocrine relations were explored in 52 students exposed to moderately stressful psychological tests demanding selective attention. Subjects with high excretion rates of adrenaline performed better during the entire stress session than did subjects with low adrenaline excretion. The level of subjective stress increased consistently throughout the session in subjects with low excretion rates of adrenaline, while it remained relatively constant in subjects with high adrenaline excretion. No consistent relationship could be demonstrated between noradrenaline excretion and the psychological variables. Possible effects on the catecholamine-excretion patterns of factors such as severity and duration of the stress are discussed.     

EFFECTS OF CHRONIC REDUCTIONS IN BRAIN CHOLINESTERASE ACTIVITY ON ACQUISITION AND EXTINCTION OF A CONDITIONED AVOIDANCE RESPONSE

R ussell , R. W., W atson , R. H. J., and F rankenhaeuser , M. Effects of chronic reductions in brain cholinesterase activity on acquisition and extinction of a conditioned avoidance response. Scand. J. Psychol ., 1961, 2 , 21–29.—Significant effects of five different levels of reduction in brain ChE activity in the white rat were found during the extinction, but not during the acquisition, of a conditioned avoidance response. The reductions were produced and chronically maintained throughout the experiment by administration of an organo-phosphorous anticholinesterase. (1) Reduced brain ChE activity was associated with differential effects on the behavior, i.e., speed of conditioning was not altered significantly, whereas speed of extinction was so affected. (2) There appears to be a 'critical level' between 60 and 65 per cent reduction of normal ChE activity below which extinction was significantly affected.     

Asymmetrical contrast effects induced by luminance and color configurations

In the two experiments, the use of a psychophysical procedure of brightness/darkness cancellation shed light on interactions between spatial arrangement and figure-ground contrast in the perceptual filling in of achromatic and colored surfaces. Achromatic and chromatic Kanizsa squares with varying contrast, contrast polarity, and inducer spacing were used to test how these factors interact in the perceptual filling in of surface brightness or darkness. The results suggest that the neuronal processing of surfaces with apparent contrast, leading to figure-ground segregation (i.e., perceptual organization), is governed by mechanisms that integrate both luminance contrast and spatial information carried by the inducing stimuli, while discarding information on contrast polarity or color. The findings are discussed in relation to earlier observations on brightness assimilation and contrast. They support theories of nonantagonistic neural mechanisms suppressing local contrast or color signs in brightness-based figure-ground percepts. Such mechanisms might be necessary to cancel potentially conflicting polarities in geometrically complex visual stimuli so that perceptual filling in resulting in the most plausible representation of figure and ground can be achieved.     

Computer‐assisted reading intervention with a phonics approach for children using cochlear implants or hearing aids

The present study examined computer‐assisted reading intervention with a phonics approach for deaf and hard of hearing (DHH) children in Sweden using cochlear implants or hearing aids, or a combination of both. The study included 48 children, 5, 6 and 7 years of age. Sixteen children with normal hearing (NH) served as a reference group. The first purpose of the study was to compare NH and DHH children's reading ability at pre and post‐intervention. The second purpose was to investigate effects of the intervention. Cognitive and demographic factors were analyzed in relation to reading improvement. Results showed no statistically significant difference for reading ability at the group level, although NH children showed overall higher reading scores at both test points. Age comparisons revealed a statistically significant higher reading ability in the NH 7‐year‐olds compared to the DHH 7‐year‐olds. The intervention proved successful for word decoding accuracy, passage comprehension and as a reduction of nonword decoding errors in both NH and DHH children. Reading improvement was associated with complex working memory and phonological processing skills in NH children. Correspondent associations were observed with visual working memory and letter knowledge in the DHH children. Age was the only demographic factor that was significantly correlated with reading improvement. The results suggest that DHH children's beginning reading may be influenced by visual strategies that might explain the reading delay in the older children.     

Who is the typical bicyclist?

Promoting bicycling is important for individual health, environmental sustainability and transport demand management. However, very few people use a bicycle on a regular basis. This paper explores what views bicyclists and non-bicyclists in England may hold about the typical bicyclist and how such views are related to bicycling behaviour and intentions. A survey was conducted among 244 bicyclists and non-bicyclists. On the basis of a range of statements on behaviour, motivation and characteristics of the typical bicyclist, four different stereotypes could be distinguished: responsible, lifestyle, commuter and hippy-go-lucky. These views differed between bicyclists and non-bicyclists. Moreover, independent of past bicycling behaviour, reported intentions to use a bicycle in the future were positively related to perceptions of the typical bicyclist as a commuter or hippy-go-lucky bicyclist. These findings have implications for encouraging bicycling, which may benefit from promoting bicycling as a common day-to-day activity rather than something that is only relevant for a few.